Direct borohydride fuel cells (DBFC) are emerging as a promising technology for portable power. The characteristics of a gold electrochemical sensor for detecting borohydride concentration were investigated. Although gold is not Faradically efficient for the borohydride oxidation, the peak current obtained from cyclic voltammetry (CV) showed a linear relationship in the investigated range of 0.1 mM-50 mM borohydride concentration with a detect limitation of 50 mu M, suggesting the same charge transfer mechanism within the investigated concentration range. Chronoamperometry results demonstrated a fast signal response, and the sensitivity was determined as 1.56 +/- 0.13 mu A/100 mu M based on the present disk electrode. (C) 2012 The Electrochemical Society. [DOI:10.1149/2.004204esl] All rights reserved.